A wolf plays with a 1-month-old puppy in its enclosure at Berlin Zoo. Johannes Eisele, AFP/Getty Images

An albino baby kangaroo peers out of the pouch of its mother at a zoo in Duisburg, western Germany. Roland Weihrauch, AFP/Getty Images

A baby elephant walks with its mother Angele to celebrate his first 100 days at the Budapest Zoo and Botanic Garden. Attila Kisbenedek, AFP/Getty Images

Two baby Indian lions play in Budapest. Attila Kisbenedek, AFP/Getty Images

Newborn ring-tailed lemur Rascal is given a hug by father Rakota at Bristol Zoo Gardens in Bristol, England. Matt Cardy, Getty Images

An Amur tiger cub crawls in a restricted area at the Pittsburgh Zoo. The cub is still too small to display in the zoo's outside yard. Baby animals are springing up at zoos worldwide. Take a look at some of the cuteness. Paul A. Selvaggio, AP

A 3-day-old zebra stands next to his mother, Zohra, at the Zoo Artis in Amsterdam. Robin Van Lonkhuijsen, AFP/Getty Images

Two young Sichuan Takins stand in their enclosure in the Berlin zoo. Listed as a vulnerable species, the Sichuan Takin is native to Tibet and southern Himalayan regions. Jan-Philipp Strobel, AFP/Getty Images

What a ball of fluff. Kali, an orphaned male polar bear cub from Point Lay, Alaska, explores his enclosure outside the infirmary at the Alaska Zoo. Bob Hallinen, AP

Don't get between this mother and her cubs. An Indian lioness roars as she lies with her cubs in their enclosure at a zoo in Budapest, Hungary. Attila Kovacs, AP

A 2-month-old baby Bennett's tree-kangaroo peers out of its mother's pouch at a zoo in the southern Russian city of Stavropol. Danil Semyonov, AFP/Getty Images

A Sumatran tiger cub looks up at her keeper at the San Francisco Zoo. Paul Chinn, AP

Madonna, a squirrel monkey, carries a 6-day-old baby on her back at a zoo in Norfolk, Va. Squirrel monkeys have the proportionately largest brain of all primates, with a brain to body mass ratio of 1-to-17. The Virginia Zoo via AP

What name would you have picked for this cutie? This baby rhino at the Australia Zoo in Beerwah, Australia, was named Mango via a Facebook competition. Ben Beaden, Australia Zoo, via Getty Images

A young tapir, born less than a month ago, stands with his mother at a zoo in Lille, France. Tapirs are most closely related to horses and rhinos. Philippe Huguen, AFP/Getty Images

The youngest member of the panda family, Xiao Liwu, plays in the snow for the first time at the San Diego Zoo. The 7-month-old cub explored his exhibit and played with mom Bai Yun, nipping and wrestling with her in the snow. More than 15 tons of fresh snow was blown into the panda's exhibit as part of an enrichment surprise. Ken Bohn, AFP/Getty Images

A newborn elephant stands at a zoo in Copenhagen. Torkil Adsersen, AFP/Getty Images

A baby gorilla extends an arm at the Gladys Porter Zoo in Brownsville, Texas, where she was born on Jan. 29. The gorilla, who was ignored by her mother, was moved to the Cincinnati Zoo. Christian Rodriguez, AP

Wesa, a 2-week-old California condor chick, is nudged by a puppet at the San Diego Zoo Safari Park. Ron Webb, a San Diego Zoo Safari Park senior condor keeper, is using a puppet to rear the chick as part of preparing Wesa to be released into the wild one day. Ken Bohn, AFP/Getty Images

An Angolan colobus monkey born at Brookfield Zoo in Illinois on March 9 is cradled by its mom, Olivia. This is the first birth of this species of colobus born at the zoo. Jim Schulz, Chicago Zoological Society, via AP

A Sumatran orangutan holds her 3-week-old baby at a zoo in Prague. Michal Cizek, AFP/Getty Images